1
|
Ali O, Szabó A. Fumonisin distorts the cellular membrane lipid profile: A mechanistic insight. Toxicology 2024; 506:153860. [PMID: 38871209 DOI: 10.1016/j.tox.2024.153860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 06/04/2024] [Accepted: 06/06/2024] [Indexed: 06/15/2024]
Abstract
Monitoring modifications in membrane lipids in association with external stimuli/agents, including fumonisins (FUMs), is a widely employed approach to assess cellular metabolic response/status. FUMs are prevalent fusariotoxins worldwide that have diverse structures with varying toxicity across species; nevertheless, they can induce metabolic disturbances and disease, including cancer. The capacity of FUMs to disrupt membrane lipids, demonstrated across numerous species and organs/tissues, is ascribed to a multitude of factors/events, which range from direct to indirect effects. Certain events are well established, whereas the potential consequences of others remain speculative. The most notable effect is their resemblance to sphingoid bases, which impacts the synthesis of ceramides leading to numerous changes in lipids' composition that are not limited to sphingolipids' composition of the membranes. The next plausible scenario involves the induction of oxidative stress, which is considered an indirect/secondary effect of FUMs. Additional modes of action include modifications of enzyme activities and nuclear signals related to lipid metabolism, although these are likely not yet fully comprehended. This review provides in-depth insight into the current state of these events and their potential mechanistic actions in modifying membrane lipids, with a focus on long-chain fatty acids. This paper also presents a detailed description of the reported modifications to membrane lipids by FUMs.
Collapse
Affiliation(s)
- Omeralfaroug Ali
- Agribiotechnology and Precision Breeding for Food Security National Laboratory, Institute of Physiology and Animal Nutrition, Department of Animal Physiology and Health, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, Kaposvár 7400, Hungary.
| | - András Szabó
- Agribiotechnology and Precision Breeding for Food Security National Laboratory, Institute of Physiology and Animal Nutrition, Department of Animal Physiology and Health, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, Kaposvár 7400, Hungary; HUN-REN-MATE Mycotoxins in the Food Chain Research Group, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, Kaposvár 7400, Hungary
| |
Collapse
|
2
|
Choconta JL, Labi V, Dumbraveanu C, Kalpachidou T, Kummer KK, Kress M. Age-related neuroimmune signatures in dorsal root ganglia of a Fabry disease mouse model. Immun Ageing 2023; 20:22. [PMID: 37173694 PMCID: PMC10176851 DOI: 10.1186/s12979-023-00346-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023]
Abstract
Pain in Fabry disease (FD) is generally accepted to result from neuronal damage in the peripheral nervous system as a consequence of excess lipid storage caused by alpha-galactosidase A (α-Gal A) deficiency. Signatures of pain arising from nerve injuries are generally associated with changes of number, location and phenotypes of immune cells within dorsal root ganglia (DRG). However, the neuroimmune processes in the DRG linked to accumulating glycosphingolipids in Fabry disease are insufficiently understood.Therefore, using indirect immune fluorescence microscopy, transmigration assays and FACS together with transcriptomic signatures associated with immune processes, we assessed age-dependent neuroimmune alterations in DRG obtained from mice with a global depletion of α-Gal A as a valid mouse model for FD. Macrophage numbers in the DRG of FD mice were unaltered, and BV-2 cells as a model for monocytic cells did not show augmented migratory reactions to glycosphingolipids exposure suggesting that these do not act as chemoattractants in FD. However, we found pronounced alterations of lysosomal signatures in sensory neurons and of macrophage morphology and phenotypes in FD DRG. Macrophages exhibited reduced morphological complexity indicated by a smaller number of ramifications and more rounded shape, which were age dependent and indicative of premature monocytic aging together with upregulated expression of markers CD68 and CD163.In our FD mouse model, the observed phenotypic changes in myeloid cell populations of the DRG suggest enhanced phagocytic and unaltered proliferative capacity of macrophages as compared to wildtype control mice. We suggest that macrophages may participate in FD pathogenesis and targeting macrophages at an early stage of FD may offer new treatment options other than enzyme replacement therapy.
Collapse
Affiliation(s)
- Jeiny Luna Choconta
- Institute of Physiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Verena Labi
- Institute of Developmental Immunology, Medical University of Innsbruck, Innsbruck, Austria
| | | | | | - Kai K Kummer
- Institute of Physiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Michaela Kress
- Institute of Physiology, Medical University of Innsbruck, Innsbruck, Austria.
| |
Collapse
|
3
|
Yang ZK, Huang XL, Peng L. Transcriptome analysis reveals gene expression changes of the basidiomycetous yeast Apiotrichum mycotoxinivorans in response to ochratoxin A exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 246:114146. [PMID: 36215880 DOI: 10.1016/j.ecoenv.2022.114146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 09/23/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Ochratoxin A (OTA) is one of the most common and deleterious mycotoxins found in food and feedstuffs worldwide; however, Apiotrichum mycotoxinivorans can detoxify OTA. Our results show that A. mycotoxinivorans GUM1709 efficiently degraded OTA, but it caused the accumulation of intracellular reactive oxygen species. The main aim of this study was to identify potential OTA-detoxifying enzymes and to explore the effects of OTA on A. mycotoxinivorans GMU1709. RNA-seq data revealed that 1643 and 1980 genes were significantly upregulated and downregulated, respectively, after OTA exposure. Functional enrichment analyses indicated that OTA exposure enhanced defense capability, protein transport, endocytosis, and energy metabolism; caused ribosomal stress; suppressed DNA replication and transcription; inhibited cell growth and division; and promoted cell death. The integration of secretome, gene expression, and molecular docking analyses revealed that two carboxypeptidase homologues (members of the metallocarboxypeptidase family) were most likely responsible for the detoxification of both extracellular and intracellular OTA. Superoxide dismutase and catalase were the main genes activated in response to oxidative stress. In addition, analysis of key genes associated with cell division and apoptosis showed that OTA exposure inhibited mitosis and promoted cell death. This study revealed the possible OTA response and detoxification mechanisms in A. mycotoxinivorans.
Collapse
Affiliation(s)
- Zhi-Kai Yang
- Innovation centre for Advanced Interdisciplinary Medicine, Key Laboratory of Biological Targeting Diagnosis, Therapy and Rehabilitation of Guangdong Higher Education Institutes, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
| | - Xue-Ling Huang
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Liang Peng
- Department of Clinical Laboratory, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| |
Collapse
|
4
|
Enterohemorrhagic Escherichia coli and a Fresh View on Shiga Toxin-Binding Glycosphingolipids of Primary Human Kidney and Colon Epithelial Cells and Their Toxin Susceptibility. Int J Mol Sci 2022; 23:ijms23136884. [PMID: 35805890 PMCID: PMC9266556 DOI: 10.3390/ijms23136884] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/07/2022] [Accepted: 06/17/2022] [Indexed: 02/06/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) are the human pathogenic subset of Shiga toxin (Stx)-producing E. coli (STEC). EHEC are responsible for severe colon infections associated with life-threatening extraintestinal complications such as the hemolytic-uremic syndrome (HUS) and neurological disturbances. Endothelial cells in various human organs are renowned targets of Stx, whereas the role of epithelial cells of colon and kidneys in the infection process has been and is still a matter of debate. This review shortly addresses the clinical impact of EHEC infections, novel aspects of vesicular package of Stx in the intestine and the blood stream as well as Stx-mediated extraintestinal complications and therapeutic options. Here follows a compilation of the Stx-binding glycosphingolipids (GSLs), globotriaosylceramide (Gb3Cer) and globotetraosylceramide (Gb4Cer) and their various lipoforms present in primary human kidney and colon epithelial cells and their distribution in lipid raft-analog membrane preparations. The last issues are the high and extremely low susceptibility of primary renal and colonic epithelial cells, respectively, suggesting a large resilience of the intestinal epithelium against the human-pathogenic Stx1a- and Stx2a-subtypes due to the low content of the high-affinity Stx-receptor Gb3Cer in colon epithelial cells. The review closes with a brief outlook on future challenges of Stx research.
Collapse
|
5
|
Need for more focus on lipid species in studies of biological and model membranes. Prog Lipid Res 2022; 86:101160. [DOI: 10.1016/j.plipres.2022.101160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 03/06/2022] [Indexed: 11/23/2022]
|
6
|
Soldati C, Lopez‐Fabuel I, Wanderlingh LG, Garcia‐Macia M, Monfregola J, Esposito A, Napolitano G, Guevara‐Ferrer M, Scotto Rosato A, Krogsaeter EK, Paquet D, Grimm CM, Montefusco S, Braulke T, Storch S, Mole SE, De Matteis MA, Ballabio A, Sampaio JL, McKay T, Johannes L, Bolaños JP, Medina DL. Repurposing of tamoxifen ameliorates CLN3 and CLN7 disease phenotype. EMBO Mol Med 2021; 13:e13742. [PMID: 34411438 PMCID: PMC8495452 DOI: 10.15252/emmm.202013742] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 07/30/2021] [Accepted: 08/02/2021] [Indexed: 11/30/2022] Open
Abstract
Batten diseases (BDs) are a group of lysosomal storage disorders characterized by seizure, visual loss, and cognitive and motor deterioration. We discovered increased levels of globotriaosylceramide (Gb3) in cellular and murine models of CLN3 and CLN7 diseases and used fluorescent-conjugated bacterial toxins to label Gb3 to develop a cell-based high content imaging (HCI) screening assay for the repurposing of FDA-approved compounds able to reduce this accumulation within BD cells. We found that tamoxifen reduced the lysosomal accumulation of Gb3 in CLN3 and CLN7 cell models, including neuronal progenitor cells (NPCs) from CLN7 patient-derived induced pluripotent stem cells (iPSC). Here, tamoxifen exerts its action through a mechanism that involves activation of the transcription factor EB (TFEB), a master gene of lysosomal function and autophagy. In vivo administration of tamoxifen to the CLN7Δex2 mouse model reduced the accumulation of Gb3 and SCMAS, decreased neuroinflammation, and improved motor coordination. These data strongly suggest that tamoxifen may be a suitable drug to treat some types of Batten disease.
Collapse
Affiliation(s)
- Chiara Soldati
- Telethon Institute of Genetics and Medicine (TIGEM), PozzuoliNaplesItaly
| | - Irene Lopez‐Fabuel
- Institute of Functional Biology and GenomicsCSICUniversity of SalamancaSalamancaSpain
- Centro de Investigación Biomédica en Red sobre Fragilidad y Envejecimiento Saludable (CIBERFES)Instituto de Salud Carlos IIIMadridSpain
- Institute of Biomedical Research of SalamancaUniversity Hospital of SalamancaCSICUniversity of SalamancaSalamancaSpain
| | - Luca G Wanderlingh
- Telethon Institute of Genetics and Medicine (TIGEM), PozzuoliNaplesItaly
| | - Marina Garcia‐Macia
- Institute of Functional Biology and GenomicsCSICUniversity of SalamancaSalamancaSpain
- Centro de Investigación Biomédica en Red sobre Fragilidad y Envejecimiento Saludable (CIBERFES)Instituto de Salud Carlos IIIMadridSpain
- Institute of Biomedical Research of SalamancaUniversity Hospital of SalamancaCSICUniversity of SalamancaSalamancaSpain
| | - Jlenia Monfregola
- Telethon Institute of Genetics and Medicine (TIGEM), PozzuoliNaplesItaly
| | | | - Gennaro Napolitano
- Telethon Institute of Genetics and Medicine (TIGEM), PozzuoliNaplesItaly
- Medical Genetics UnitDepartment of Medical and Translational ScienceFederico II UniversityNaplesItaly
| | | | - Anna Scotto Rosato
- Faculty of MedicineWalther Straub Institute of Pharmacology and ToxicologyLudwig‐Maximilians UniversityMunichGermany
| | - Einar K Krogsaeter
- Faculty of MedicineWalther Straub Institute of Pharmacology and ToxicologyLudwig‐Maximilians UniversityMunichGermany
| | - Dominik Paquet
- Institute for Stroke and Dementia Research (ISD)University HospitalLMU MunichMunichGermany
- Munich Cluster for Systems Neurology (SyNergy)MunichGermany
| | - Christian M Grimm
- Faculty of MedicineWalther Straub Institute of Pharmacology and ToxicologyLudwig‐Maximilians UniversityMunichGermany
| | - Sandro Montefusco
- Telethon Institute of Genetics and Medicine (TIGEM), PozzuoliNaplesItaly
| | - Thomas Braulke
- Department Osteology & BiomechanicsUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Stephan Storch
- University Children's Research@Kinder‐UKEUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Sara E Mole
- Medical Research Council Laboratory for Molecular Cell Biology and UCL Great Ormond Street Institute of Child HealthUniversity College LondonLondonUK
| | - Maria A De Matteis
- Telethon Institute of Genetics and Medicine (TIGEM), PozzuoliNaplesItaly
- Department of Molecular Medicine and Medical BiotechnologyUniversity of Napoli Federico IINaplesItaly
| | - Andrea Ballabio
- Telethon Institute of Genetics and Medicine (TIGEM), PozzuoliNaplesItaly
- Medical Genetics UnitDepartment of Medical and Translational ScienceFederico II UniversityNaplesItaly
- Baylor College of MedicineHoustonTXUSA
- Jan and Dan Duncan Neurological Research InstituteTexas Children's HospitalHoustonTXUSA
| | - Julio L Sampaio
- Cellular and Chemical Biology DepartmentInstitut Curie, U1143 INSERM, UMR3666 CNRSPSL Research UniversityParisFrance
| | - Tristan McKay
- School of Healthcare ScienceManchester Metropolitan UniversityManchesterUK
| | - Ludger Johannes
- Cellular and Chemical Biology DepartmentInstitut Curie, U1143 INSERM, UMR3666 CNRSPSL Research UniversityParisFrance
| | - Juan P Bolaños
- Institute of Functional Biology and GenomicsCSICUniversity of SalamancaSalamancaSpain
- Centro de Investigación Biomédica en Red sobre Fragilidad y Envejecimiento Saludable (CIBERFES)Instituto de Salud Carlos IIIMadridSpain
- Institute of Biomedical Research of SalamancaUniversity Hospital of SalamancaCSICUniversity of SalamancaSalamancaSpain
| | - Diego L Medina
- Telethon Institute of Genetics and Medicine (TIGEM), PozzuoliNaplesItaly
- Medical Genetics UnitDepartment of Medical and Translational ScienceFederico II UniversityNaplesItaly
| |
Collapse
|
7
|
The Protein Toxins Ricin and Shiga Toxin as Tools to Explore Cellular Mechanisms of Internalization and Intracellular Transport. Toxins (Basel) 2021; 13:toxins13060377. [PMID: 34070659 PMCID: PMC8227415 DOI: 10.3390/toxins13060377] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/12/2021] [Accepted: 05/22/2021] [Indexed: 12/18/2022] Open
Abstract
Protein toxins secreted by bacteria and found in plants can be threats to human health. However, their extreme toxicity can also be exploited in different ways, e.g., to produce hybrid toxins directed against cancer cells and to study transport mechanisms in cells. Investigations during the last decades have shown how powerful these molecules are as tools in cell biological research. Here, we first present a partly historical overview, with emphasis on Shiga toxin and ricin, of how such toxins have been used to characterize processes and proteins of importance for their trafficking. In the second half of the article, we describe how one can now use toxins to investigate the role of lipid classes for intracellular transport. In recent years, it has become possible to quantify hundreds of lipid species using mass spectrometry analysis. Thus, it is also now possible to explore the importance of lipid species in intracellular transport. The detailed analyses of changes in lipids seen under conditions of inhibited toxin transport reveal previously unknown connections between syntheses of lipid classes and demonstrate the ability of cells to compensate under given conditions.
Collapse
|
8
|
Ribeiro IM, Souto PCS, Borbely AU, Tanabe ELL, Cadavid A, Alvarez AM, Bueno J, Agudelo O, Robles RG, Ayala-Ramírez P, Sacerdoti F, Szasz T, Damiano AE, Ibarra C, Escudero C, Lima VV, Giachini FR. The limited knowledge of placental damage due to neglected infections: ongoing problems in Latin America. Syst Biol Reprod Med 2021; 66:151-169. [PMID: 32482148 DOI: 10.1080/19396368.2020.1753850] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The placenta works as a selective barrier, protecting the fetus from potential infections that may affect the maternal organism during pregnancy. In this review, we will discuss several challenging infections that are common within Latin American countries and that may affect the maternal-fetal interface and pose risks to fetal development. Specifically, we will focus on emerging infectious diseases including the arboviruses, malaria, leishmaniasis, and the bacterial foodborne disease caused by Shiga toxin-producing Escherichia coli. We will also highlight some topics of interest currently being studied by research groups that comprise an international effort aimed at filling the knowledge gaps in this field. These topics address the relationship between exposure to microorganisms and placental abnormalities, congenital anomalies, and complications of pregnancy. ABBREVIATIONS ADE: antibody-dependent enhancement; CCL2: monocyte chemoattractant protein-1; CCL3: macrophage inflammatory protein-1 α; CCL5: chemokine (C-C motif) ligand 5; CHIKV: chikungunya virus; DCL: diffuse cutaneous leishmaniasis; DENV: dengue virus; Gb3: glycolipid globotriaosylceramyde; HIF: hypoxia-inducible factor; HUS: hemolytic uremic syndrome; IFN: interferon; Ig: immunoglobulins; IL: interleukin; IUGR: intrauterine growth restriction; LCL: localized cutaneous leishmaniasis; LPS: lipopolysaccharid; MCL: mucocutaneous leishmaniasis; NO: nitric oxide; PCR: polymerase chain reaction; PGF: placental growth factor; PM: placental malaria; RIVATREM: Red Iberoamericana de Alteraciones Vasculares em transtornos del Embarazo; sVEGFR: soluble vascular endothelial growth factor receptor; STEC: shiga toxin-producing Escherichia coli; stx: shiga toxin protein; TNF: tumor necrosis factor; TOAS: T cell original antigenic sin; Var2CSA: variant surface antigen 2-CSA; VEGF: vascular endothelial growth factor; VL: visceral leishmaniasis; WHO: world health organization; YFV: yellow fever virus; ZIKV: Zika virus.
Collapse
Affiliation(s)
- Isabela Moreti Ribeiro
- Laboratory of Vascular Biology and Histopathology, Institute of Health Sciences and Health, Federal University of Mato Grosso , Barra Do Garcas, Brazil
| | - Paula Cristina Souza Souto
- Laboratory of Vascular Biology and Histopathology, Institute of Health Sciences and Health, Federal University of Mato Grosso , Barra Do Garcas, Brazil
| | - Alexandre U Borbely
- Cell Biology Laboratory, Institute of Health and Biological Sciences, Federal University of Alagoas , Alagoas, Brazil
| | - Eloiza Lopes Lira Tanabe
- Cell Biology Laboratory, Institute of Health and Biological Sciences, Federal University of Alagoas , Alagoas, Brazil
| | - Angela Cadavid
- Grupo Reproducción, Facultad De Medicina Universidad De Antioquia , Medellin, Colombia
| | - Angela M Alvarez
- Grupo Reproducción, Facultad De Medicina Universidad De Antioquia , Medellin, Colombia
| | - Julio Bueno
- Grupo Reproducción, Facultad De Medicina Universidad De Antioquia , Medellin, Colombia
| | - Olga Agudelo
- Grupo Salud Y Comunidad, Facultad De Medicina Universidad De Antioquia , Medellin, Colombia
| | - Reggie García Robles
- Physiological Sciences Department, Faculty of Medicine, Pontificia Universidad Javeriana , Bogotá, Colombia
| | - Paola Ayala-Ramírez
- Human Genetics Institute, Facultad De Medicina, Pontificia Universidad Javeriana , Bogotá, Colombia
| | - Flavia Sacerdoti
- Laboratorio De Fisiopatogenia, Instituto De Fisiología Y Biofísica Bernardo Houssay (IFIBIO)- CONICET- Departamento De Fisiología, Facultad De Medicina, Universidad De Buenos Aires . Buenos Aires, Argentina
| | - Theodora Szasz
- Departamento of Physiology, Augusta University , Augusta, USA
| | - Alicia E Damiano
- Cátedra De Biología Celular Y Molecular, Departamento De Ciencias Biológicas, Facultad De Farmacia Y Bioquímica, Universidad De Buenos Aires . Buenos Aires, Argentina.,Laboratorio De Biología De La Reproducción, Instituto De Fisiología Y Biofísica Bernardo Houssay (IFIBIO)- CONICET- Facultad De Medicina, Universidad De Buenos Aires . Buenos Aires, Argentina
| | - Cristina Ibarra
- Cátedra De Biología Celular Y Molecular, Departamento De Ciencias Biológicas, Facultad De Farmacia Y Bioquímica, Universidad De Buenos Aires . Buenos Aires, Argentina
| | - Carlos Escudero
- Vascular Physiology Laboratory, Group of Research and Innovation in Vascular Health (GRIVAS Health), Basic Sciences Department Faculty of Sciences, Universidad Del Bio-Bio , Chillan, Chile
| | - Victor V Lima
- Laboratory of Vascular Biology and Histopathology, Institute of Health Sciences and Health, Federal University of Mato Grosso , Barra Do Garcas, Brazil
| | - Fernanda R Giachini
- Laboratory of Vascular Biology and Histopathology, Institute of Health Sciences and Health, Federal University of Mato Grosso , Barra Do Garcas, Brazil
| |
Collapse
|
9
|
Brandel A, Aigal S, Lagies S, Schlimpert M, Meléndez AV, Xu M, Lehmann A, Hummel D, Fisch D, Madl J, Eierhoff T, Kammerer B, Römer W. The Gb3-enriched CD59/flotillin plasma membrane domain regulates host cell invasion by Pseudomonas aeruginosa. Cell Mol Life Sci 2021; 78:3637-3656. [PMID: 33555391 PMCID: PMC8038999 DOI: 10.1007/s00018-021-03766-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 12/22/2020] [Accepted: 01/15/2021] [Indexed: 12/11/2022]
Abstract
The opportunistic pathogen Pseudomonas aeruginosa has gained precedence over the years due to its ability to develop resistance to existing antibiotics, thereby necessitating alternative strategies to understand and combat the bacterium. Our previous work identified the interaction between the bacterial lectin LecA and its host cell glycosphingolipid receptor globotriaosylceramide (Gb3) as a crucial step for the engulfment of P. aeruginosa via the lipid zipper mechanism. In this study, we define the LecA-associated host cell membrane domain by pull-down and mass spectrometry analysis. We unraveled a predilection of LecA for binding to saturated, long fatty acyl chain-containing Gb3 species in the extracellular membrane leaflet and an induction of dynamic phosphatidylinositol (3,4,5)-trisphosphate (PIP3) clusters at the intracellular leaflet co-localizing with sites of LecA binding. We found flotillins and the GPI-anchored protein CD59 not only to be an integral part of the LecA-interacting membrane domain, but also majorly influencing bacterial invasion as depletion of either of these host cell proteins resulted in about 50% reduced invasiveness of the P. aeruginosa strain PAO1. In summary, we report that the LecA-Gb3 interaction at the extracellular leaflet induces the formation of a plasma membrane domain enriched in saturated Gb3 species, CD59, PIP3 and flotillin thereby facilitating efficient uptake of PAO1.
Collapse
Affiliation(s)
- Annette Brandel
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
| | - Sahaja Aigal
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Simon Lagies
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- Center for Biological Systems Analysis, University of Freiburg, Habsburgerstraße 49, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany
| | - Manuel Schlimpert
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- Center for Biological Systems Analysis, University of Freiburg, Habsburgerstraße 49, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany
| | - Ana Valeria Meléndez
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany
| | - Maokai Xu
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
| | - Anika Lehmann
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
| | - Daniel Hummel
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Department of Biochemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211, Geneva, Switzerland
| | - Daniel Fisch
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- Department of Infectious Disease, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2AZ, UK
| | - Josef Madl
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, and Faculty of Medicine, University of Freiburg, Elsässer Straße 2q, 79110, Freiburg, Germany
| | - Thorsten Eierhoff
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Clinic for Vascular and Endovascular Surgery, University Hospital Münster, Albert Schweitzer Campus 1, 48149, Münster, Germany
| | - Bernd Kammerer
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Center for Biological Systems Analysis, University of Freiburg, Habsburgerstraße 49, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany
| | - Winfried Römer
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany.
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany.
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany.
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany.
| |
Collapse
|
10
|
Lee KS, Lee J, Lee P, Kim CU, Kim DJ, Jeong YJ, Park YJ, Tesh VL, Lee MS. Exosomes released from Shiga toxin 2a-treated human macrophages modulate inflammatory responses and induce cell death in toxin receptor expressing human cells. Cell Microbiol 2020; 22:e13249. [PMID: 32772454 DOI: 10.1111/cmi.13249] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 07/02/2020] [Accepted: 07/24/2020] [Indexed: 12/13/2022]
Abstract
Shiga toxins (Stxs) produced by Stx-producing Escherichia coli are the primarily virulence factors of hemolytic uremic syndrome and central nervous system (CNS) impairment. Although the precise mechanisms of toxin dissemination remain unclear, Stxs bind to extracellular vesicles (EVs). Exosomes, a subset of EVs, may play a key role in Stx-mediated renal injury. To test this hypothesis, we isolated exosomes from monocyte-derived macrophages in the presence of Stx2a or Stx2 toxoids. Macrophage-like differentiated THP-1 cells treated with Stxs secreted Stx-associated exosomes (Stx-Exo) of 90-130 nm in diameter, which induced cytotoxicity in recipient cells in a toxin receptor globotriaosylceramide (Gb3 )-dependent manner. Stx2-Exo engulfed by Gb3 -positive cells were translocated to the endoplasmic reticulum in the human proximal tubule epithelial cell line HK-2. Stx2-Exo contained pro-inflammatory cytokine mRNAs and proteins and induced more severe inflammation than purified Stx2a accompanied by greater death of target cells such as human renal or retinal pigment epithelial cells. Blockade of exosome biogenesis using the pharmacological inhibitor GW4869 reduced Stx2-Exo-mediated human renal cell death. Stx2-Exo isolated from human primary monocyte-derived macrophages activated caspase 3/7 and resulted in significant cell death in primary human renal cortical epithelial cells. Based on these results, we speculate that Stx-containing exosomes derived from macrophages may exacerbate cytotoxicity and inflammation and trigger cell death in toxin-sensitive cells. Therapeutic interventions targeting Stx-containing exosomes may prevent or ameliorate Stx-mediated acute vascular dysfunction.
Collapse
Affiliation(s)
- Kyung-Soo Lee
- Environmental Diseases Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea.,Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, South Korea
| | - Jieun Lee
- Environmental Diseases Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Pureum Lee
- Environmental Diseases Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea.,Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, South Korea
| | - Chang-Ung Kim
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Doo-Jin Kim
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Yu-Jin Jeong
- Environmental Diseases Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Young-Jun Park
- Environmental Diseases Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea.,Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, South Korea
| | - Vernon L Tesh
- Department of Microbial Pathogenesis and Immunology, Texas A&M University, College of Medicine, Bryan, Texas, USA
| | - Moo-Seung Lee
- Environmental Diseases Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea.,Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, South Korea
| |
Collapse
|
11
|
Lingelem ABD, Kavaliauskiene S, Halsne R, Klokk TI, Surma MA, Klose C, Skotland T, Sandvig K. Diacylglycerol kinase and phospholipase D inhibitors alter the cellular lipidome and endosomal sorting towards the Golgi apparatus. Cell Mol Life Sci 2020; 78:985-1009. [PMID: 32447426 PMCID: PMC7897626 DOI: 10.1007/s00018-020-03551-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 12/13/2022]
Abstract
The membrane lipids diacylglycerol (DAG) and phosphatidic acid (PA) are important second messengers that can regulate membrane transport by recruiting proteins to the membrane and by altering biophysical membrane properties. DAG and PA are involved in the transport from the Golgi apparatus to endosomes, and we have here investigated whether changes in these lipids might be important for regulation of transport to the Golgi using the protein toxin ricin. Modulation of DAG and PA levels using DAG kinase (DGK) and phospholipase D (PLD) inhibitors gave a strong increase in retrograde ricin transport, but had little impact on ricin recycling or degradation. Inhibitor treatment strongly affected the endosome morphology, increasing endosomal tubulation and size. Furthermore, ricin was present in these tubular structures together with proteins known to regulate retrograde transport. Using siRNA to knock down different isoforms of PLD and DGK, we found that several isoforms of PLD and DGK are involved in regulating ricin transport to the Golgi. Finally, by performing lipidomic analysis we found that the DGK inhibitor gave a weak, but expected, increase in DAG levels, while the PLD inhibitor gave a strong and unexpected increase in DAG levels, showing that it is important to perform lipidomic analysis when using inhibitors of lipid metabolism.
Collapse
Affiliation(s)
- Anne Berit Dyve Lingelem
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.,Department of Forensic Biology, Oslo University Hospital, Oslo, Norway
| | - Simona Kavaliauskiene
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Ruth Halsne
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.,Department of Forensic Biology, Oslo University Hospital, Oslo, Norway
| | - Tove Irene Klokk
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.,Regional Committees for Medical and Health Research Ethics, University of Oslo, Oslo, Norway
| | | | | | - Tore Skotland
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Kirsten Sandvig
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway. .,Department of Biosciences, University of Oslo, Oslo, Norway.
| |
Collapse
|
12
|
Mühlen S, Dersch P. Treatment Strategies for Infections With Shiga Toxin-Producing Escherichia coli. Front Cell Infect Microbiol 2020; 10:169. [PMID: 32435624 PMCID: PMC7218068 DOI: 10.3389/fcimb.2020.00169] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 03/31/2020] [Indexed: 01/07/2023] Open
Abstract
Infections with Shiga toxin-producing Escherichia coli (STEC) cause outbreaks of severe diarrheal disease in children and the elderly around the world. The severe complications associated with toxin production and release range from bloody diarrhea and hemorrhagic colitis to hemolytic-uremic syndrome, kidney failure, and neurological issues. As the use of antibiotics for treatment of the infection has long been controversial due to reports that antibiotics may increase the production of Shiga toxin, the recommended therapy today is mainly supportive. In recent years, a variety of alternative treatment approaches such as monoclonal antibodies or antisera directed against Shiga toxin, toxin receptor analogs, and several vaccination strategies have been developed and evaluated in vitro and in animal models. A few strategies have progressed to the clinical trial phase. Here, we review the current understanding of and the progress made in the development of treatment options against STEC infections and discuss their potential.
Collapse
Affiliation(s)
- Sabrina Mühlen
- Institute for Infectiology, University of Münster, Münster, Germany.,German Center for Infection Research (DZIF), Associated Site University of Münster, Münster, Germany
| | - Petra Dersch
- Institute for Infectiology, University of Münster, Münster, Germany.,German Center for Infection Research (DZIF), Associated Site University of Münster, Münster, Germany
| |
Collapse
|
13
|
Sibold J, Kettelhoit K, Vuong L, Liu F, Werz DB, Steinem C. Synthesis of Gb 3 Glycosphingolipids with Labeled Head Groups: Distribution in Phase-Separated Giant Unilamellar Vesicles. Angew Chem Int Ed Engl 2019; 58:17805-17813. [PMID: 31529754 PMCID: PMC6899692 DOI: 10.1002/anie.201910148] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/09/2019] [Indexed: 11/22/2022]
Abstract
The receptor lipid Gb3 is responsible for the specific internalization of Shiga toxin (STx) into cells. The head group of Gb3 defines the specificity of STx binding, and the backbone with different fatty acids is expected to influence its localization within membranes impacting membrane organization and protein internalization. To investigate this influence, a set of Gb3 glycosphingolipids labeled with a BODIPY fluorophore attached to the head group was synthesized. C24 fatty acids, saturated, unsaturated, α-hydroxylated derivatives, and a combination thereof, were attached to the sphingosine backbone. The synthetic Gb3 glycosphingolipids were reconstituted into coexisting liquid-ordered (lo )/liquid-disordered (ld ) giant unilamellar vesicles (GUVs), and STx binding was verified by fluorescence microscopy. Gb3 with the C24:0 fatty acid partitioned mostly in the lo phase, while the unsaturated C24:1 fatty acid distributes more into the ld phase. The α-hydroxylation does not influence its partitioning.
Collapse
Affiliation(s)
- Jeremias Sibold
- Georg-August-Universität GöttingenInstitute of Organic and Biomolecular ChemistryTammannstr. 237077GöttingenGermany
| | - Katharina Kettelhoit
- Technische Universität BraunschweigInstitute of Organic ChemistryHagenring 3038106BraunschweigGermany
| | - Loan Vuong
- Georg-August-Universität GöttingenInstitute of Organic and Biomolecular ChemistryTammannstr. 237077GöttingenGermany
| | - Fangyuan Liu
- Georg-August-Universität GöttingenInstitute of Organic and Biomolecular ChemistryTammannstr. 237077GöttingenGermany
| | - Daniel B. Werz
- Technische Universität BraunschweigInstitute of Organic ChemistryHagenring 3038106BraunschweigGermany
| | - Claudia Steinem
- Georg-August-Universität GöttingenInstitute of Organic and Biomolecular ChemistryTammannstr. 237077GöttingenGermany
- Max Planck Institute for Dynamics and Self OrganizationAm Faßberg 1737077GöttingenGermany
| |
Collapse
|
14
|
Sibold J, Kettelhoit K, Vuong L, Liu F, Werz DB, Steinem C. Synthesis of Gb
3
Glycosphingolipids with Labeled Head Groups: Distribution in Phase‐Separated Giant Unilamellar Vesicles. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201910148] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jeremias Sibold
- Georg-August-Universität GöttingenInstitute of Organic and Biomolecular Chemistry Tammannstr. 2 37077 Göttingen Germany
| | - Katharina Kettelhoit
- Technische Universität BraunschweigInstitute of Organic Chemistry Hagenring 30 38106 Braunschweig Germany
| | - Loan Vuong
- Georg-August-Universität GöttingenInstitute of Organic and Biomolecular Chemistry Tammannstr. 2 37077 Göttingen Germany
| | - Fangyuan Liu
- Georg-August-Universität GöttingenInstitute of Organic and Biomolecular Chemistry Tammannstr. 2 37077 Göttingen Germany
| | - Daniel B. Werz
- Technische Universität BraunschweigInstitute of Organic Chemistry Hagenring 30 38106 Braunschweig Germany
| | - Claudia Steinem
- Georg-August-Universität GöttingenInstitute of Organic and Biomolecular Chemistry Tammannstr. 2 37077 Göttingen Germany
- Max Planck Institute for Dynamics and Self Organization Am Faßberg 17 37077 Göttingen Germany
| |
Collapse
|
15
|
Riley RT, Merrill AH. Ceramide synthase inhibition by fumonisins: a perfect storm of perturbed sphingolipid metabolism, signaling, and disease. J Lipid Res 2019; 60:1183-1189. [PMID: 31048407 PMCID: PMC6602133 DOI: 10.1194/jlr.s093815] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 04/25/2019] [Indexed: 01/18/2023] Open
Abstract
Fumonisins are mycotoxins that cause diseases of plants and, when consumed by animals, can damage liver, kidney, lung, brain, and other organs, alter immune function, and cause developmental defects and cancer. They structurally resemble sphingolipids (SLs), and studies nearly 30 years ago discovered that the most prevalent fumonisin [fumonisin B1 (FB1)] potently inhibits ceramide synthases (CerSs), enzymes that use fatty acyl-CoAs to N-acylate sphinganine (Sa), sphingosine (So), and other sphingoid bases. CerS inhibition by FB1 triggers a "perfect storm" of perturbations in structural and signaling SLs that include: reduced formation of dihydroceramides, ceramides, and complex SLs; elevated Sa and So and their 1-phosphates, novel 1-deoxy-sphingoid bases; and alteration of additional lipid metabolites from interrelated pathways. Moreover, because the initial enzyme of sphingoid base biosynthesis remains active (sometimes with increased activity), the impact is multiplied by the continued production of damaging metabolites. Evidence from many studies, including characterization of knockout mice for specific CerSs and analyses of human blood (which found that FB1 intake is associated with elevated Sa 1-phosphate), has consistently pointed to CerS as the proximate target of FB1 It is also apparent that the changes in multiple bioactive lipids and related biologic processes account for the ensuing spectrum of animal and plant disease. Thus, the diseases caused by fumonisins can be categorized as "sphingolipidoses" (in these cases, due to defective SL biosynthesis), and the lessons learned about the consequences of CerS inhibition should be borne in mind when contemplating other naturally occurring and synthetic compounds (and genetic manipulations) that interfere with SL metabolism.
Collapse
Affiliation(s)
- Ronald T Riley
- College of Public Health, Department of Environmental Health Science, University of Georgia, Athens, GA 30602
| | - Alfred H Merrill
- School of Biological Sciences and the Parker H. Petit Institute for Bioengineering and Bioscience Georgia Institute of Technology, Atlanta, GA 30332
| |
Collapse
|
16
|
Jiménez-Rojo N, Riezman H. On the road to unraveling the molecular functions of ether lipids. FEBS Lett 2019; 593:2378-2389. [PMID: 31166014 DOI: 10.1002/1873-3468.13465] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 05/28/2019] [Accepted: 05/29/2019] [Indexed: 12/12/2022]
Abstract
Ether lipids are glycerolipids further classified into alkyl-ether and alkenyl-ether (also termed plasmalogens) lipids. The two ether lipid subclasses share the first steps of their synthesis. However, alkyl-ether and alkenyl-ether lipids differ in their structure and physico-chemical properties (featuring different head groups) and, thus, probably in their functions. Ether lipids have intermittent distribution across the evolutionary tree and defects in their synthesis have been shown to perturb cellular homeostasis and lead to disease in humans. Here, we review their structure, their interactions with other lipids, and their potential roles in cellular functions, such as membrane homeostasis and membrane trafficking. Moreover, we discuss still unclear aspects of these lipids such as their subcellular distribution, and the need to unravel their molecular functions as well as how novel tools to study lipid biology will help clarify these aspects.
Collapse
Affiliation(s)
- Noemi Jiménez-Rojo
- NCCR Chemical Biology, Department of Biochemistry, University of Geneva, Switzerland
| | - Howard Riezman
- NCCR Chemical Biology, Department of Biochemistry, University of Geneva, Switzerland
| |
Collapse
|
17
|
Sacerdoti F, Scalise ML, Burdet J, Amaral MM, Franchi AM, Ibarra C. Shiga Toxin-Producing Escherichia coli Infections during Pregnancy. Microorganisms 2018; 6:E111. [PMID: 30360505 PMCID: PMC6313425 DOI: 10.3390/microorganisms6040111] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 10/17/2018] [Accepted: 10/19/2018] [Indexed: 01/08/2023] Open
Abstract
Gastrointestinal infection with Shiga toxin-producing Escherichia coli (STEC) causes diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS), characterized by hemolytic anemia, thrombocytopenia and acute renal failure. The main virulence factor of STEC is Shiga toxin (Stx), which is responsible for HUS development. STEC can produce Stx type 1 and/or 2 (Stx1, Stx2) and their variants, Stx2 being more frequently associated with severe cases of HUS. This pathology occurs in 5⁻15% of cases with STEC infection when Stx gain access to the bloodstream and causes damage in the target organs such as the kidney and brain. STEC infections affect mainly young children, although the large HUS outbreak with a new Stx2-producing STEC O104:H4 in Europe in 2011 involved more adults than children, and women were over-represented. Maternal infections during pregnancy are associated with adverse pregnancy outcomes. Studies in rats showed that Stx2 binds to the utero-placental unit and causes adverse pregnancy outcomes. In this article, we provide a brief overview of Stx2 action on placental tissues and discuss whether they might cause pregnancy loss or preterm birth.
Collapse
Affiliation(s)
- Flavia Sacerdoti
- Laboratorio de Fisiopatogenia, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay-CONICET), Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, Buenos Aires 1121, Argentina.
| | - María Luján Scalise
- Laboratorio de Fisiopatogenia, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay-CONICET), Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, Buenos Aires 1121, Argentina.
| | - Juliana Burdet
- Laboratorio de Hematología, Hospital Universitario Austral, Pilar, Buenos Aires 1629, Argentina.
| | - María Marta Amaral
- Laboratorio de Fisiopatogenia, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay-CONICET), Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, Buenos Aires 1121, Argentina.
| | - Ana María Franchi
- CEFYBO-CONICET, Universidad de Buenos Aires, Buenos Aires 1121, Argentina.
| | - Cristina Ibarra
- Laboratorio de Fisiopatogenia, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay-CONICET), Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, Buenos Aires 1121, Argentina.
| |
Collapse
|
18
|
Kavaliauskiene S, Dyve Lingelem AB, Skotland T, Sandvig K. Protection against Shiga Toxins. Toxins (Basel) 2017; 9:E44. [PMID: 28165371 PMCID: PMC5331424 DOI: 10.3390/toxins9020044] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 01/18/2017] [Accepted: 01/19/2017] [Indexed: 12/12/2022] Open
Abstract
Shiga toxins consist of an A-moiety and five B-moieties able to bind the neutral glycosphingolipid globotriaosylceramide (Gb3) on the cell surface. To intoxicate cells efficiently, the toxin A-moiety has to be cleaved by furin and transported retrogradely to the Golgi apparatus and to the endoplasmic reticulum. The enzymatically active part of the A-moiety is then translocated to the cytosol, where it inhibits protein synthesis and in some cell types induces apoptosis. Protection of cells can be provided either by inhibiting binding of the toxin to cells or by interfering with any of the subsequent steps required for its toxic effect. In this article we provide a brief overview of the interaction of Shiga toxins with cells, describe some compounds and conditions found to protect cells against Shiga toxins, and discuss whether they might also provide protection in animals and humans.
Collapse
Affiliation(s)
- Simona Kavaliauskiene
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, N-0379 Oslo, Norway.
- Center for Cancer Biomedicine, Faculty of Medicine, Oslo University Hospital, N-0379 Oslo, Norway.
| | - Anne Berit Dyve Lingelem
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, N-0379 Oslo, Norway.
- Center for Cancer Biomedicine, Faculty of Medicine, Oslo University Hospital, N-0379 Oslo, Norway.
| | - Tore Skotland
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, N-0379 Oslo, Norway.
- Center for Cancer Biomedicine, Faculty of Medicine, Oslo University Hospital, N-0379 Oslo, Norway.
| | - Kirsten Sandvig
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, N-0379 Oslo, Norway.
- Center for Cancer Biomedicine, Faculty of Medicine, Oslo University Hospital, N-0379 Oslo, Norway.
- Department of Biosciences, University of Oslo, N-0316 Oslo, Norway.
| |
Collapse
|
19
|
Determining the Turnover of Glycosphingolipid Species by Stable-Isotope Tracer Lipidomics. J Mol Biol 2016; 428:4856-4866. [PMID: 27363608 DOI: 10.1016/j.jmb.2016.06.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/16/2016] [Accepted: 06/17/2016] [Indexed: 01/08/2023]
Abstract
In this study, we used water-soluble stable mass isotope precursors to measure the turnover of endogenous ceramide (Cer) and glycosphingolipids (GSLs) in HEp-2 cells. Cells incubated in the presence of [13C-U]glucose showed rapid incorporation of hexose residues with an increased mass of 6Da into GSLs. Different turnover rates of GSL classes and their molecular species were observed. Approximately 30% of the glucosylceramide, 50% of the lactosylceramide, and 50% of the globotriaosylceramide species showed a much slower turnover than the rest. This demonstrates the existence of different lipid pools, where a certain fraction of species survived for a long time in the cells. The species with the shortest N-amidated fatty acyl groups (C16:0 and C18:0) showed a more rapid turnover than those with the longest N-amidated fatty acids (C24:0 and C24:1). Experiments with addition of [13C-U]serine were performed to study de novo synthesis of Cer from serine and palmitoyl-CoA. These experiments revealed that de novo synthesis contributes to a minor extent to the total synthesis of new sphingolipids and showed that there is a more rapid formation of the longest Cer species (C24:0 and C24:1) than of the shortest species (C16:0), that is, the opposite as observed for the GSLs in the experiments with [13C-U]glucose. In conclusion, this FLUX lipidomics experimental approach with the addition of [13C-U]glucose to cells allows us to not only study the total turnover but also permit observations of lipid intermediates and metabolic flow of endogenous GSL species at the molecular lipid level.
Collapse
|
20
|
Shiga Toxins Activate the NLRP3 Inflammasome Pathway To Promote Both Production of the Proinflammatory Cytokine Interleukin-1β and Apoptotic Cell Death. Infect Immun 2015; 84:172-86. [PMID: 26502906 DOI: 10.1128/iai.01095-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 10/16/2015] [Indexed: 02/06/2023] Open
Abstract
Shiga toxin (Stx)-mediated immune responses, including the production of the proinflammatory cytokines tumor necrosis-α (TNF-α) and interleukin-1β (IL-1β), may exacerbate vascular damage and accelerate lethality. However, the immune signaling pathway activated in response to Stx is not well understood. Here, we demonstrate that enzymatically active Stx, which leads to ribotoxic stress, triggers NLRP3 inflammasome-dependent caspase-1 activation and IL-1β secretion in differentiated macrophage-like THP-1 (D-THP-1) cells. The treatment of cells with a chemical inhibitor of glycosphingolipid biosynthesis, which suppresses the expression of the Stx receptor globotriaosylceramide and subsequent endocytosis of the toxin, substantially blocked activation of the NLRP3 inflammasome and processing of caspase-1 and IL-1β. Processing and release of both caspase-1 and IL-1β were significantly reduced or abolished in Stx-intoxicated D-THP-1 cells in which the expression of NLRP3 or ASC was stably knocked down. Furthermore, Stx mediated the activation of caspases involved in apoptosis in an NLRP3- or ASC-dependent manner. In Stx-intoxicated cells, the NLRP3 inflammasome triggered the activation of caspase-8/3, leading to the initiation of apoptosis, in addition to caspase-1-dependent pyroptotic cell death. Taken together, these results suggest that Stxs trigger the NLRP3 inflammasome pathway to release proinflammatory IL-1β as well as to promote apoptotic cell death.
Collapse
|
21
|
Sacerdoti F, Amaral M, Aisemberg J, Cymeryng C, Franchi A, Ibarra C. Involvement of hypoxia and inflammation in early pregnancy loss mediated by Shiga toxin type 2. Placenta 2015; 36:674-80. [DOI: 10.1016/j.placenta.2015.03.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 03/04/2015] [Accepted: 03/06/2015] [Indexed: 10/23/2022]
|
22
|
Tyler A, Johansson A, Karlsson T, Gudey SK, Brännström T, Grankvist K, Behnam-Motlagh P. Targeting glucosylceramide synthase induction of cell surface globotriaosylceramide (Gb3) in acquired cisplatin-resistance of lung cancer and malignant pleural mesothelioma cells. Exp Cell Res 2015; 336:23-32. [PMID: 26004871 DOI: 10.1016/j.yexcr.2015.05.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 05/11/2015] [Accepted: 05/13/2015] [Indexed: 01/02/2023]
Abstract
BACKGROUND Acquired resistance to cisplatin treatment is a caveat when treating patients with non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma (MPM). Ceramide increases in response to chemotherapy, leading to proliferation arrest and apoptosis. However, a tumour stress activation of glucosylceramide synthase (GCS) follows to eliminate ceramide by formation of glycosphingolipids (GSLs) such as globotriaosylceramide (Gb3), the functional receptor of verotoxin-1. Ceramide elimination enhances cell proliferation and apoptosis blockade, thus stimulating tumor progression. GSLs transactivate multidrug resistance 1/P-glycoprotein (MDR1) and multidrug resistance-associated protein 1 (MRP1) expression which further prevents ceramide accumulation and stimulates drug efflux. We investigated the expression of Gb3, MDR1 and MRP1 in NSCLC and MPM cells with acquired cisplatin resistance, and if GCS activity or MDR1 pump inhibitors would reduce their expression and reverse cisplatin-resistance. METHODS Cell surface expression of Gb3, MDR1 and MRP1 and intracellular expression of MDR1 and MRP1 was analyzed by flow cytometry and confocal microscopy on P31 MPM and H1299 NSCLC cells and subline cells with acquired cisplatin resistance. The effect of GCS inhibitor PPMP and MDR1 pump inhibitor cyclosporin A for 72h on expression and cisplatin cytotoxicity was tested. RESULTS The cisplatin-resistant cells expressed increased cell surface Gb3. Cell surface Gb3 expression of resistant cells was annihilated by PPMP whereas cyclosporin A decreased Gb3 and MDR1 expression in H1299 cells. No decrease of MDR1 by PPMP was noted in using flow cytometry, whereas a decrease of MDR1 in H1299 and H1299res was indicated with confocal microscopy. No certain co-localization of Gb3 and MDR1 was noted. PPMP, but not cyclosporin A, potentiated cisplatin cytotoxicity in all cells. CONCLUSIONS Cell surface Gb3 expression is a likely tumour biomarker for acquired cisplatin resistance of NSCLC and MPM cells. Tumour cell resistance to MDR1 inhibitors of cell surface MDR1 and Gb3 could explain the aggressiveness of NSCLC and MPM. Therapy with GCS activity inhibitors or toxin targeting of the Gb3 receptor may substantially reduce acquired cisplatin drug resistance of NSCLC and MPM cells.
Collapse
Affiliation(s)
- Andreas Tyler
- Department of Medical Biosciences, Umeå University, S-901 85 Umea, Sweden.
| | - Anders Johansson
- Department of Odontology, Umeå University, S-901 85 Umea, Sweden
| | - Terese Karlsson
- Department of Radiation Sciences, Oncology, S-901 85 Umea, Sweden
| | - Shyam Kumar Gudey
- Department of Medical Biosciences, Umeå University, S-901 85 Umea, Sweden
| | - Thomas Brännström
- Department of Medical Biosciences, Umeå University, S-901 85 Umea, Sweden
| | - Kjell Grankvist
- Department of Medical Biosciences, Umeå University, S-901 85 Umea, Sweden
| | | |
Collapse
|
23
|
Bergan J, Skotland T, Lingelem ABD, Simm R, Spilsberg B, Lindbäck T, Sylvänne T, Simolin H, Ekroos K, Sandvig K. The ether lipid precursor hexadecylglycerol protects against Shiga toxins. Cell Mol Life Sci 2014; 71:4285-300. [PMID: 24740796 PMCID: PMC11113769 DOI: 10.1007/s00018-014-1624-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 03/12/2014] [Accepted: 04/01/2014] [Indexed: 11/24/2022]
Abstract
Shiga toxin-producing Escherichia coli bacteria cause hemorrhagic colitis and hemolytic uremic syndrome in humans. Currently, only supportive treatment is available for diagnosed patients. We show here that 24-h pretreatment with an ether lipid precursor, the alkylglycerol sn-1-O-hexadecylglycerol (HG), protects HEp-2 cells against Shiga toxin and Shiga toxin 2. Also the endothelial cell lines HMEC-1 and HBMEC are protected against Shiga toxins after HG pretreatment. In contrast, the corresponding acylglycerol, DL-α-palmitin, has no effect on Shiga toxicity. Although HG treatment provides a strong protection (~30 times higher IC₅₀) against Shiga toxin, only a moderate reduction in toxin binding was observed, suggesting that retrograde transport of the toxin from the plasma membrane to the cytosol is perturbed. Furthermore, endocytosis of Shiga toxin and retrograde sorting from endosomes to the Golgi apparatus remain intact, but transport from the Golgi to the endoplasmic reticulum is inhibited by HG treatment. As previously described, HG reduces the total level of all quantified glycosphingolipids to 50-70% of control, including the Shiga toxin receptor globotriaosylceramide (Gb3), in HEp-2 cells. In accordance with this, we find that interfering with Gb3 biosynthesis by siRNA-mediated knockdown of Gb3 synthase for 24 h causes a similar cytotoxic protection and only a moderate reduction in toxin binding (to 70% of control cells). Alkylglycerols, including HG, have been administered to humans for investigation of therapeutic roles in disorders where ether lipid biosynthesis is deficient, as well as in cancer therapy. Further studies may reveal if HG can also have a therapeutic potential in Shiga toxin-producing E. coli infections.
Collapse
Affiliation(s)
- Jonas Bergan
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0379 Oslo, Norway
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Tore Skotland
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0379 Oslo, Norway
| | - Anne Berit Dyve Lingelem
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0379 Oslo, Norway
| | - Roger Simm
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0379 Oslo, Norway
| | - Bjørn Spilsberg
- Section of Bacteriology-Food and GMO, Norwegian Veterinary Institute, Oslo, Norway
| | - Toril Lindbäck
- Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, Oslo, Norway
| | | | | | | | - Kirsten Sandvig
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0379 Oslo, Norway
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| |
Collapse
|
24
|
Abstract
Shiga toxin (Stx) is one of the most potent bacterial toxins known. Stx is found in Shigella dysenteriae 1 and in some serogroups of Escherichia coli (called Stx1 in E. coli). In addition to or instead of Stx1, some E. coli strains produce a second type of Stx, Stx2, that has the same mode of action as Stx/Stx1 but is antigenically distinct. Because subtypes of each toxin have been identified, the prototype toxin for each group is now designated Stx1a or Stx2a. The Stxs consist of two major subunits, an A subunit that joins noncovalently to a pentamer of five identical B subunits. The A subunit of the toxin injures the eukaryotic ribosome and halts protein synthesis in target cells. The function of the B pentamer is to bind to the cellular receptor, globotriaosylceramide, Gb3, found primarily on endothelial cells. The Stxs traffic in a retrograde manner within the cell, such that the A subunit of the toxin reaches the cytosol only after the toxin moves from the endosome to the Golgi and then to the endoplasmic reticulum. In humans infected with Stx-producing E. coli, the most serious manifestation of the disease, hemolytic-uremic syndrome, is more often associated with strains that produce Stx2a rather than Stx1a, and that relative toxicity is replicated in mice and baboons. Stx1a and Stx2a also exhibit differences in cytotoxicity to various cell types, bind dissimilarly to receptor analogs or mimics, induce differential chemokine responses, and have several distinctive structural characteristics.
Collapse
Affiliation(s)
- Angela R. Melton-Celsa
- Department of Microbiology & Immunology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814,
| |
Collapse
|
25
|
Quinn PJ. Sphingolipid symmetry governs membrane lipid raft structure. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1922-30. [DOI: 10.1016/j.bbamem.2014.02.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 02/24/2014] [Accepted: 02/27/2014] [Indexed: 02/07/2023]
|
26
|
Phuyal S, Hessvik NP, Skotland T, Sandvig K, Llorente A. Regulation of exosome release by glycosphingolipids and flotillins. FEBS J 2014; 281:2214-27. [PMID: 24605801 DOI: 10.1111/febs.12775] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 02/06/2014] [Accepted: 03/04/2014] [Indexed: 12/14/2022]
Abstract
Exosomes are released by cells after fusion of multivesicular bodies with the plasma membrane. The molecular mechanism of this process is still unclear. We investigated the role of sphingolipids and flotillins, which constitute a raft-associated family of proteins, in the release of exosomes. Interestingly, our results show that dl-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol, an inhibitor of glucosylceramide synthase, seemed to affect the composition of exosomes released from PC-3 cells. However, the inhibition of ceramide formation from the de novo pathway by fumonisin B1 did not affect exosome secretion. Moreover, in contrast to findings obtained with other cell lines published so far, inhibition of neutral sphingomyelinase 2, an enzyme that catalyzes the formation of ceramide from sphingomyelin, did not inhibit the secretion of exosomes in PC-3 cells. Finally, small interfering RNA-mediated downregulation of flotillin-1 and flotillin-2 did not significantly change the levels of released exosomes as such, but seemed to affect the composition of exosomes. In conclusion, our results reveal the involvement of glycosphingolipids and flotillins in the release of exosomes from PC-3 cells, and indicate that the role of ceramide in exosome formation may be cell-dependent.
Collapse
Affiliation(s)
- Santosh Phuyal
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital - The Norwegian Radium Hospital, Norway; Center for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Norway
| | | | | | | | | |
Collapse
|
27
|
Kavaliauskiene S, Nymark CM, Bergan J, Simm R, Sylvänne T, Simolin H, Ekroos K, Skotland T, Sandvig K. Cell density-induced changes in lipid composition and intracellular trafficking. Cell Mol Life Sci 2014; 71:1097-116. [PMID: 23921715 PMCID: PMC11113877 DOI: 10.1007/s00018-013-1441-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 07/24/2013] [Accepted: 07/25/2013] [Indexed: 12/11/2022]
Abstract
Cell density is one of the extrinsic factors to which cells adapt their physiology when grown in culture. However, little is known about the molecular changes which occur during cell growth and how cellular responses are then modulated. In many cases, inhibitors, drugs or growth factors used for in vitro studies change the rate of cell proliferation, resulting in different cell densities in control and treated samples. Therefore, for a comprehensive data analysis, it is essential to understand the implications of cell density on the molecular level. In this study, we have investigated how lipid composition changes during cell growth, and the consequences it has for transport of Shiga toxin. By quantifying 308 individual lipid species from 17 different lipid classes, we have found that the levels and species distribution of several lipids change during cell growth, with the major changes observed for diacylglycerols, phosphatidic acids, cholesterol esters, and lysophosphatidylethanolamines. In addition, there is a reduced binding and retrograde transport of Shiga toxin in high density cells which lead to reduced intoxication by the toxin. In conclusion, our data provide novel information on how lipid composition changes during cell growth in culture, and how these changes can modulate intracellular trafficking.
Collapse
Affiliation(s)
- Simona Kavaliauskiene
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, 0379 Oslo, Norway
- Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Carl-Martin Nymark
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, 0379 Oslo, Norway
- Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
| | - Jonas Bergan
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, 0379 Oslo, Norway
- Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Roger Simm
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, 0379 Oslo, Norway
- Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
| | | | | | | | - Tore Skotland
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, 0379 Oslo, Norway
- Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
| | - Kirsten Sandvig
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, 0379 Oslo, Norway
- Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway
- Department of Biosciences, University of Oslo, Oslo, Norway
| |
Collapse
|
28
|
Sandvig K, Bergan J, Kavaliauskiene S, Skotland T. Lipid requirements for entry of protein toxins into cells. Prog Lipid Res 2014; 54:1-13. [PMID: 24462587 DOI: 10.1016/j.plipres.2014.01.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 01/15/2014] [Accepted: 01/15/2014] [Indexed: 01/05/2023]
Abstract
The plant toxin ricin and the bacterial toxin Shiga toxin both belong to a group of protein toxins having one moiety that binds to the cell surface, and another, enzymatically active moiety, that enters the cytosol and inhibits protein synthesis by inactivating ribosomes. Both toxins travel all the way from the cell surface to endosomes, the Golgi apparatus and the ER before the ribosome-inactivating moiety enters the cytosol. Shiga toxin binds to the neutral glycosphingolipid Gb3 at the cell surface and is therefore dependent on this lipid for transport into the cells, whereas ricin binds both glycoproteins and glycolipids with terminal galactose. The different steps of transport used by these toxins have specific requirements for lipid species, and with the recent developments in mass spectrometry analysis of lipids and microscopical and biochemical dissection of transport in cells, we are starting to see the complexity of endocytosis and intracellular transport. In this article we describe lipid requirements and the consequences of lipid changes for the entry and intoxication with ricin and Shiga toxin. These toxins can be a threat to human health, but can also be exploited for diagnosis and therapy, and have proven valuable as tools to study intracellular transport.
Collapse
Affiliation(s)
- Kirsten Sandvig
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway; Department of Biosciences, University of Oslo, Oslo, Norway.
| | - Jonas Bergan
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.
| | - Simona Kavaliauskiene
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway; Department of Biosciences, University of Oslo, Oslo, Norway.
| | - Tore Skotland
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.
| |
Collapse
|
29
|
Schütte OM, Ries A, Orth A, Patalag LJ, Römer W, Steinem C, Werz DB. Influence of Gb3 glycosphingolipids differing in their fatty acid chain on the phase behaviour of solid supported membranes: chemical syntheses and impact of Shiga toxin binding. Chem Sci 2014. [DOI: 10.1039/c4sc01290a] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
30
|
Bergan J, Skotland T, Sylvänne T, Simolin H, Ekroos K, Sandvig K. The ether lipid precursor hexadecylglycerol causes major changes in the lipidome of HEp-2 cells. PLoS One 2013; 8:e75904. [PMID: 24098742 PMCID: PMC3786967 DOI: 10.1371/journal.pone.0075904] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 08/20/2013] [Indexed: 01/22/2023] Open
Abstract
The ether-lipid precursor sn-1-O-hexadecylglycerol (HG) can be used to compensate for early metabolic defects in ether-lipid biosynthesis. To investigate a possible metabolic link between ether-linked phospholipids and the rest of the cellular lipidome, we incubated HEp-2 cells with HG. Mass spectrometry analysis revealed major changes in the lipidome of HG-treated cells compared to that of untreated cells or cells treated with palmitin, a control substance for HG containing an acyl group instead of the ether group. We present quantitative data for a total of 154 species from 17 lipid classes. These species are those constituting more than 2% of their lipid class for most lipid classes, but more than 1% for the ether lipids and glycosphingolipids. In addition to the expected ability of HG to increase the levels of ether-linked glycerophospholipids with 16 carbon atoms in the sn-1 position, this precursor also decreased the amounts of glycosphingolipids and increased the amounts of ceramide, phosphatidylinositol and lysophosphatidylinositol. However, incubation with palmitin, the fatty acyl analogue of HG, also increased the amounts of ceramide and phosphatidylinositols. Thus, changes in these lipid classes were not ether lipid-dependent. No major effects were observed for the other lipid classes, and cellular functions such as growth and endocytosis were unaffected. The data presented clearly demonstrate the importance of performing detailed quantitative lipidomic studies to reveal how the metabolism of ether-linked glycerophospholipids is coupled to that of glycosphingolipids and ester-linked glycerophospholipids, especially phosphatidylinositols.
Collapse
Affiliation(s)
- Jonas Bergan
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Tore Skotland
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | | | | | | | - Kirsten Sandvig
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
- Department of Biosciences, University of Oslo, Oslo, Norway
- * E-mail:
| |
Collapse
|
31
|
Zumbrun SD, Melton-Celsa AR, Smith MA, Gilbreath JJ, Merrell DS, O’Brien AD. Dietary choice affects Shiga toxin-producing Escherichia coli (STEC) O157:H7 colonization and disease. Proc Natl Acad Sci U S A 2013; 110:E2126-33. [PMID: 23690602 PMCID: PMC3677460 DOI: 10.1073/pnas.1222014110] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The likelihood that a single individual infected with the Shiga toxin (Stx)-producing, food-borne pathogen Escherichia coli O157:H7 will develop a life-threatening sequela called the hemolytic uremic syndrome is unpredictable. We reasoned that conditions that enhance Stx binding and uptake within the gut after E. coli O157:H7 infection should result in greater disease severity. Because the receptor for Stx, globotriaosylceramide, is up-regulated in the presence of butyrate in vitro, we asked whether a high fiber diet (HFD) that reportedly enhances butyrate production by normal gut flora can influence the outcome of an E. coli O157 infection in mice. To address that question, groups of BALB/c mice were fed high (10%) or low (2%) fiber diets and infected with E. coli O157:H7 strain 86-24 (Stx2+). Mice fed an HFD exhibited a 10- to 100-fold increase in colonization, lost 15% more body weight, exhibited signs of morbidity, and had 25% greater mortality relative to the low fiber diet (LFD)-fed group. Additionally, sections of intestinal tissue from HFD-fed mice bound more Stx1 and expressed more globotriaosylceramide than did such sections from LFD-fed mice. Furthermore, the gut microbiota of HFD-fed mice compared with LFD-fed mice contained reduced levels of native Escherichia species, organisms that might protect the gut from colonization by incoming E. coli O157:H7. Taken together, these results suggest that susceptibility to infection and subsequent disease after ingestion of E. coli O157:H7 may depend, at least in part, on individual diet and/or the capacity of the commensal flora to produce butyrate.
Collapse
Affiliation(s)
- Steven D. Zumbrun
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799
| | - Angela R. Melton-Celsa
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799
| | - Mark A. Smith
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799
| | - Jeremy J. Gilbreath
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799
| | - D. Scott Merrell
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799
| | - Alison D. O’Brien
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799
| |
Collapse
|
32
|
Kouzel IU, Pohlentz G, Storck W, Radamm L, Hoffmann P, Bielaszewska M, Bauwens A, Cichon C, Schmidt MA, Mormann M, Karch H, Müthing J. Association of Shiga toxin glycosphingolipid receptors with membrane microdomains of toxin-sensitive lymphoid and myeloid cells. J Lipid Res 2013; 54:692-710. [PMID: 23248329 PMCID: PMC3617944 DOI: 10.1194/jlr.m031781] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 12/14/2012] [Indexed: 11/20/2022] Open
Abstract
Glycosphingolipids (GSLs) of the globo-series constitute specific receptors for Shiga toxins (Stxs) released by certain types of pathogenic Escherichia coli strains. Stx-loaded leukocytes may act as transporter cells in the blood and transfer the toxin to endothelial target cells. Therefore, we performed a thorough investigation on the expression of globo-series GSLs in serum-free cultivated Raji and Jurkat cells, representing B- and T-lymphocyte descendants, respectively, as well as THP-1 and HL-60 cells of the monocyte and granulocyte lineage, respectively. The presence of Stx-receptors in GSL preparations of Raji and THP-1 cells and the absence in Jurkat and HL-60 cells revealed high compliance of solid-phase immunodetection assays with the expression profiles of receptor-related glycosyltransferases, performed by qRT-PCR analysis, and Stx2-caused cellular damage. Canonical microdomain association of Stx GSL receptors, sphingomyelin, and cholesterol in membranes of Raji and THP-1 cells was assessed by comparative analysis of detergent-resistant membrane (DRM) and nonDRM fractions obtained by density gradient centrifugation and showed high correlation based on nonparametric statistical analysis. Our comprehensive study on the expression of Stx-receptors and their subcellular distribution provides the basis for exploring the functional role of lipid raft-associated Stx-receptors in cells of leukocyte origin.
Collapse
Affiliation(s)
- Ivan U. Kouzel
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
| | | | - Wiebke Storck
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
| | - Lena Radamm
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
| | - Petra Hoffmann
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
| | | | - Andreas Bauwens
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
| | - Christoph Cichon
- Institute of Infectiology, University of Münster, D-48149 Münster, Germany
| | | | - Michael Mormann
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
| | - Helge Karch
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
| | - Johannes Müthing
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
- Interdisciplinary Center for Clinical Research (IZKF), University of Münster, D-48149 Münster, Germany
| |
Collapse
|
33
|
Bauwens A, Betz J, Meisen I, Kemper B, Karch H, Müthing J. Facing glycosphingolipid-Shiga toxin interaction: dire straits for endothelial cells of the human vasculature. Cell Mol Life Sci 2013; 70:425-57. [PMID: 22766973 PMCID: PMC11113656 DOI: 10.1007/s00018-012-1060-z] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 05/25/2012] [Accepted: 06/14/2012] [Indexed: 12/23/2022]
Abstract
The two major Shiga toxin (Stx) types, Stx1 and Stx2, produced by enterohemorrhagic Escherichia coli (EHEC) in particular injure renal and cerebral microvascular endothelial cells after transfer from the human intestine into the circulation. Stxs are AB(5) toxins composed of an enzymatically active A subunit and the pentameric B subunit, which preferentially binds to the glycosphingolipid globotriaosylceramide (Gb3Cer/CD77). This review summarizes the current knowledge on Stx-caused cellular injury and the structural diversity of Stx receptors as well as the initial molecular interaction of Stxs with the human endothelium of different vascular beds. The varying lipoforms of Stx receptors and their spatial organization in lipid rafts suggest a central role in different modes of receptor-mediated endocytosis and intracellular destiny of the toxins. The design and development of tailored Stx neutralizers targeting the oligosaccharide-toxin recognition event has become a very real prospect to ameliorate or prevent life-threatening renal and neurological complications.
Collapse
Affiliation(s)
- Andreas Bauwens
- Institute for Hygiene, University of Münster, Robert-Koch-Str. 41, 48149 Münster, Germany
| | - Josefine Betz
- Institute for Hygiene, University of Münster, Robert-Koch-Str. 41, 48149 Münster, Germany
| | - Iris Meisen
- Institute for Hygiene, University of Münster, Robert-Koch-Str. 41, 48149 Münster, Germany
- Interdisciplinary Center for Clinical Research, University of Münster, Domagkstr. 3, 48149 Münster, Germany
| | - Björn Kemper
- Center for Biomedical Optics and Photonics, University of Münster, Robert-Koch-Str. 45, 48149 Münster, Germany
| | - Helge Karch
- Institute for Hygiene, University of Münster, Robert-Koch-Str. 41, 48149 Münster, Germany
| | - Johannes Müthing
- Institute for Hygiene, University of Münster, Robert-Koch-Str. 41, 48149 Münster, Germany
- Interdisciplinary Center for Clinical Research, University of Münster, Domagkstr. 3, 48149 Münster, Germany
| |
Collapse
|
34
|
Chinnapen DJF, Hsieh WT, te Welscher YM, Saslowsky DE, Kaoutzani L, Brandsma E, D'Auria L, Park H, Wagner JS, Drake KR, Kang M, Benjamin T, Ullman MD, Costello CE, Kenworthy AK, Baumgart T, Massol RH, Lencer WI. Lipid sorting by ceramide structure from plasma membrane to ER for the cholera toxin receptor ganglioside GM1. Dev Cell 2013; 23:573-86. [PMID: 22975326 DOI: 10.1016/j.devcel.2012.08.002] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 04/06/2012] [Accepted: 08/04/2012] [Indexed: 01/26/2023]
Abstract
The glycosphingolipid GM1 binds cholera toxin (CT) on host cells and carries it retrograde from the plasma membrane (PM) through endosomes, the trans-Golgi (TGN), and the endoplasmic reticulum (ER) to induce toxicity. To elucidate how a membrane lipid can specify trafficking in these pathways, we synthesized GM1 isoforms with alternate ceramide domains and imaged their trafficking in live cells. Only GM1 with unsaturated acyl chains sorted efficiently from PM to TGN and ER. Toxin binding, which effectively crosslinks GM1 lipids, was dispensable, but membrane cholesterol and the lipid raft-associated proteins actin and flotillin were required. The results implicate a protein-dependent mechanism of lipid sorting by ceramide structure and provide a molecular explanation for the diversity and specificity of retrograde trafficking by CT in host cells.
Collapse
Affiliation(s)
- Daniel J-F Chinnapen
- Division of Gastroenterology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Bergan J, Dyve Lingelem AB, Simm R, Skotland T, Sandvig K. Shiga toxins. Toxicon 2012; 60:1085-107. [PMID: 22960449 DOI: 10.1016/j.toxicon.2012.07.016] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 06/19/2012] [Accepted: 07/25/2012] [Indexed: 02/03/2023]
Abstract
Shiga toxins are virulence factors produced by the bacteria Shigella dysenteriae and certain strains of Escherichia coli. There is currently no available treatment for disease caused by these toxin-producing bacteria, and understanding the biology of the Shiga toxins might be instrumental in addressing this issue. In target cells, the toxins efficiently inhibit protein synthesis by inactivating ribosomes, and they may induce signaling leading to apoptosis. To reach their cytoplasmic target, Shiga toxins are endocytosed and transported by a retrograde pathway to the endoplasmic reticulum, before the enzymatically active moiety is translocated to the cytosol. The toxins thereby serve as powerful tools to investigate mechanisms of intracellular transport. Although Shiga toxins are a serious threat to human health, the toxins may be exploited for medical purposes such as cancer therapy or imaging.
Collapse
Affiliation(s)
- Jonas Bergan
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Norway
| | | | | | | | | |
Collapse
|
36
|
Annexin A1 and A2: roles in retrograde trafficking of Shiga toxin. PLoS One 2012; 7:e40429. [PMID: 22792315 PMCID: PMC3391278 DOI: 10.1371/journal.pone.0040429] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Accepted: 06/06/2012] [Indexed: 01/05/2023] Open
Abstract
Annexins constitute a family of calcium and membrane binding proteins. As annexin A1 and A2 have previously been linked to various membrane trafficking events, we initiated this study to investigate the role of these annexins in the uptake and intracellular transport of the bacterial Shiga toxin (Stx) and the plant toxin ricin. Once endocytosed, both toxins are retrogradely transported from endosomes to the Golgi apparatus and the endoplasmic reticulum before being targeted to the cytosol where they inhibit protein synthesis. This study was performed to obtain new information both about toxin transport and the function of annexin A1 and annexin A2. Our data show that depletion of annexin A1 or A2 alters the retrograde transport of Stx but not ricin, without affecting toxin binding or internalization. Knockdown of annexin A1 increases Golgi transport of Stx, whereas knockdown of annexin A2 slightly decreases the same transport step. Interestingly, annexin A1 was found in proximity to cytoplasmic phospholipase A2 (cPLA2), and the basal as well as the increased Golgi transport of Stx upon annexin A1 knockdown is dependent on cPLA2 activity. In conclusion, annexin A1 and A2 have different roles in Stx transport to the trans-Golgi network. The most prominent role is played by annexin A1 which normally works as a negative regulator of retrograde transport from the endosomes to the Golgi network, most likely by complex formation and inhibition of cPLA2.
Collapse
|
37
|
Engedal N, Skotland T, Torgersen ML, Sandvig K. Shiga toxin and its use in targeted cancer therapy and imaging. Microb Biotechnol 2012; 4:32-46. [PMID: 21255370 PMCID: PMC3023029 DOI: 10.1111/j.1751-7915.2010.00180.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Shiga and the Shiga‐like toxins are related protein toxins produced by Shigella dysenteriae and certain strains of Escherichia coli. These toxins are composed of two non‐covalently attached, modular parts: the A moiety (StxA) containing the enzymatically active A1 fragment, and the non‐toxic, pentameric binding moiety (StxB). Stx binds specifically to the glycosphingolipid globotriaosylceramide (Gb3) at the surface of target cells and is then internalized by endocytosis. Subsequently, in toxin‐sensitive cells, the Stx/Gb3 complex is transported in a retrograde manner via the Golgi apparatus to the endoplasmic reticulum, where the enzymatically active part of Stx is translocated to the cytosol, enabling it to irreversibly inhibit protein synthesis via modification of ribosomal 28S RNA. Whereas Gb3 shows a relatively restricted expression in normal human tissues, it has been reported to be highly expressed in many types of cancers. This review gives a brief introduction to Stx and its intracellular transport. Furthermore, after a description of Gb3 and the methods that are currently used to detect its cellular expression, we provide an updated overview of the published reports on Gb3 overexpression in human cancers. Finally, we discuss the possibility of utilizing Stx or StxB coupled to therapeutic compounds or contrast agents in targeted cancer therapy and imaging.
Collapse
Affiliation(s)
- Nikolai Engedal
- Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, N-0310 Oslo, Norway
| | | | | | | |
Collapse
|
38
|
Herzog R, Schuhmann K, Schwudke D, Sampaio JL, Bornstein SR, Schroeder M, Shevchenko A. LipidXplorer: a software for consensual cross-platform lipidomics. PLoS One 2012; 7:e29851. [PMID: 22272252 PMCID: PMC3260173 DOI: 10.1371/journal.pone.0029851] [Citation(s) in RCA: 275] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 12/05/2011] [Indexed: 01/14/2023] Open
Abstract
LipidXplorer is the open source software that supports the quantitative characterization of complex lipidomes by interpreting large datasets of shotgun mass spectra. LipidXplorer processes spectra acquired on any type of tandem mass spectrometers; it identifies and quantifies molecular species of any ionizable lipid class by considering any known or assumed molecular fragmentation pathway independently of any resource of reference mass spectra. It also supports any shotgun profiling routine, from high throughput top-down screening for molecular diagnostic and biomarker discovery to the targeted absolute quantification of low abundant lipid species. Full documentation on installation and operation of LipidXplorer, including tutorial, collection of spectra interpretation scripts, FAQ and user forum are available through the wiki site at: https://wiki.mpi-cbg.de/wiki/lipidx/index.php/Main_Page.
Collapse
Affiliation(s)
- Ronny Herzog
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- Department of Internal Medicine III, Carl Gustav Carus Clinics of Dresden University of Technology, Dresden, Germany
| | - Kai Schuhmann
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- Department of Internal Medicine III, Carl Gustav Carus Clinics of Dresden University of Technology, Dresden, Germany
| | - Dominik Schwudke
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | - Julio L. Sampaio
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Stefan R. Bornstein
- Department of Internal Medicine III, Carl Gustav Carus Clinics of Dresden University of Technology, Dresden, Germany
| | - Michael Schroeder
- Biotechnology Centre, Dresden University of Technology, Dresden, Germany
| | - Andrej Shevchenko
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- * E-mail:
| |
Collapse
|
39
|
Merrill AH. Sphingolipid and glycosphingolipid metabolic pathways in the era of sphingolipidomics. Chem Rev 2011; 111:6387-422. [PMID: 21942574 PMCID: PMC3191729 DOI: 10.1021/cr2002917] [Citation(s) in RCA: 527] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Indexed: 12/15/2022]
Affiliation(s)
- Alfred H Merrill
- School of Biology, and the Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia 30332-0230, USA.
| |
Collapse
|
40
|
Kingston D, Chang H, Ensser A, Lee HR, Lee J, Lee SH, Jung JU, Cho NH. Inhibition of retromer activity by herpesvirus saimiri tip leads to CD4 downregulation and efficient T cell transformation. J Virol 2011; 85:10627-38. [PMID: 21849449 PMCID: PMC3187508 DOI: 10.1128/jvi.00757-11] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Accepted: 08/08/2011] [Indexed: 11/20/2022] Open
Abstract
The mammalian retromer is an evolutionally conserved protein complex composed of a vacuolar protein sorting trimer (Vps 26/29/35) that participates in cargo recognition and a sorting nexin (SNX) dimer that binds to endosomal membranes. The retromer plays an important role in efficient retrograde transport for endosome-to-Golgi retrieval of the cation-independent mannose-6-phosphate receptor (CI-MPR), a receptor for lysosomal hydrolases, and other endosomal proteins. This ultimately contributes to the control of cell growth, cell adhesion, and cell migration. The herpesvirus saimiri (HVS) tyrosine kinase-interacting protein (Tip), required for the immortalization of primary T lymphocytes, targets cellular signaling molecules, including Lck tyrosine kinases and the p80 endosomal trafficking protein. Despite the pronounced effects of HVS Tip on T cell signal transduction, the details of its activity on T cell immortalization remain elusive. Here, we report that the amino-terminal conserved, glutamate-rich sequence of Tip specifically interacts with the retromer subunit Vps35 and that this interaction not only causes the redistribution of Vps35 from the early endosome to the lysosome but also drastically inhibits retromer activity, as measured by decreased levels of CI-MPR and lower activities of cellular lysosomal hydrolases. Physiologically, the inhibition of intracellular retromer activity by Tip is ultimately linked to the downregulation of CD4 surface expression and to the efficient in vitro immortalization of primary human T cells to interleukin-2 (IL-2)-independent permanent growth. Therefore, HVS Tip uniquely targets the retromer complex to impair the intracellular trafficking functions of infected cells, ultimately contributing to efficient T cell transformation.
Collapse
Affiliation(s)
- Dior Kingston
- Department of Microbiology and Molecular Genetics and Tumor Virology Division, New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
- Institute for Research in Biomedicine, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland
| | - Heesoon Chang
- Department of Microbiology and Molecular Genetics and Tumor Virology Division, New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
- Molecular Microbiology & Immunology, University of Southern California, School of Medicine, 2011 Zonal Avenue, HMR401, Los Angeles, California 90033
| | - Armin Ensser
- Institut für Klinische und Molekulare Virologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054 Erlangen, Germany
| | - Hye-Ra Lee
- Department of Microbiology and Molecular Genetics and Tumor Virology Division, New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
- Molecular Microbiology & Immunology, University of Southern California, School of Medicine, 2011 Zonal Avenue, HMR401, Los Angeles, California 90033
| | - Jongsoo Lee
- Department of Microbiology and Molecular Genetics and Tumor Virology Division, New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
- Molecular Microbiology & Immunology, University of Southern California, School of Medicine, 2011 Zonal Avenue, HMR401, Los Angeles, California 90033
| | - Sun-Hwa Lee
- Molecular Microbiology & Immunology, University of Southern California, School of Medicine, 2011 Zonal Avenue, HMR401, Los Angeles, California 90033
| | - Jae Ung Jung
- Department of Microbiology and Molecular Genetics and Tumor Virology Division, New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
- Molecular Microbiology & Immunology, University of Southern California, School of Medicine, 2011 Zonal Avenue, HMR401, Los Angeles, California 90033
| | - Nam-Hyuk Cho
- Department of Microbiology and Molecular Genetics and Tumor Virology Division, New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
- Department of Microbiology and Immunology, Seoul National University College of Medicine, and Institute of Endemic Disease, Seoul National University Medical Research Center and Bundang Hospital, Jongno-Gu, Seoul 110-799, Republic of Korea
| |
Collapse
|
41
|
Role of phospholipase A(2) in retrograde transport of ricin. Toxins (Basel) 2011; 3:1203-19. [PMID: 22069763 PMCID: PMC3202871 DOI: 10.3390/toxins3091203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 08/25/2011] [Accepted: 09/16/2011] [Indexed: 12/03/2022] Open
Abstract
Ricin is a protein toxin classified as a bioterror agent, for which there are no known treatment options available after intoxication. It is composed of an enzymatically active A-chain connected by a disulfide bond to a cell binding B-chain. After internalization by endocytosis, ricin is transported retrogradely to the Golgi and ER, from where the ricin A-chain is translocated to the cytosol where it inhibits protein synthesis and thus induces cell death. We have identified cytoplasmic phospholipase A2 (PLA2) as an important factor in ricin retrograde transport. Inhibition of PLA2 protects against ricin challenge, however the toxin can still be endocytosed and transported to the Golgi. Interestingly, ricin transport from the Golgi to the ER is strongly impaired in response to PLA2 inhibition. Confocal microscopy analysis shows that ricin is still colocalized with the trans-Golgi marker TGN46 in the presence of PLA2 inhibitor, but less is colocalized with the cis-Golgi marker GM130. We propose that PLA2 inhibition results in impaired ricin transport through the Golgi stack, thus preventing it from reaching the ER. Consequently, ricin cannot be translocated to the cytosol to exert its toxic action.
Collapse
|
42
|
Abstract
Some proteins and lipids traffic from the plasma membrane to the trans Golgi network (TGN)/Golgi apparatus and the endoplasmic reticulum, via the retrograde transport route. Endosomes are an obligatory through station. Whether early, recycling and late endosomes all hand off material to the TGN have remained a matter of debate. In this review, we give a short historical overview on how retrograde transport was discovered and explored. We then summarize and critically discuss data that have been put forward in favour of the existence of trafficking interfaces between each of the different endocytic localizations and the TGN. We finally point out some conceptual and technological challenges that will have to be met to establish definite conclusions for each of these scenarios.
Collapse
Affiliation(s)
- Ludger Johannes
- Traffic, Signaling, and Delivery Laboratory, Centre de Recherche, Institut Curie, CNRS UMR144, 26 rue d'Ulm, 75248 Paris Cedex 05, France.
| | | |
Collapse
|
43
|
Betz J, Bielaszewska M, Thies A, Humpf HU, Dreisewerd K, Karch H, Kim KS, Friedrich AW, Müthing J. Shiga toxin glycosphingolipid receptors in microvascular and macrovascular endothelial cells: differential association with membrane lipid raft microdomains. J Lipid Res 2011; 52:618-34. [PMID: 21252262 DOI: 10.1194/jlr.m010819] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Vascular damage caused by Shiga toxin (Stx)-producing Escherichia coli is largely mediated by Stxs, which in particular, injure microvascular endothelial cells in the kidneys and brain. The majority of Stxs preferentially bind to the glycosphingolipid (GSL) globotriaosylceramide (Gb3Cer) and, to a lesser extent, to globotetraosylceramide (Gb4Cer). As clustering of receptor GSLs in lipid rafts is a functional requirement for Stxs, we analyzed the distribution of Gb3Cer and Gb4Cer to membrane microdomains of human brain microvascular endothelial cells (HBMECs) and macrovascular EA.hy 926 endothelial cells by means of anti-Gb3Cer and anti-Gb4Cer antibodies. TLC immunostaining coupled with infrared matrix-assisted laser desorption/ionization (IR-MALDI) mass spectrometry revealed structural details of various lipoforms of Stx receptors and demonstrated their major distribution in detergent-resistant membranes (DRMs) compared with nonDRM fractions of HBMECs and EA.hy 926 cells. A significant preferential partition of different receptor lipoforms carrying C24:0/C24:1 or C16:0 fatty acid and sphingosine to DRMs was not detected in either cell type. Methyl-β-cyclodextrin (MβCD)-mediated cholesterol depletion resulted in only partial destruction of lipid rafts, accompanied by minor loss of GSLs in HBMECs. In contrast, almost entire disintegration of lipid rafts accompanied by roughly complete loss of GSLs was detected in EA.hy 926 cells after removal of cholesterol, indicating more stable microdomains in HBMECs. Our findings provide first evidence for differently stable microdomains in human endothelial cells from different vascular beds and should serve as the basis for further exploring the functional role of lipid raft-associated Stx receptors in different cell types.
Collapse
Affiliation(s)
- Josefine Betz
- Institutes for Hygiene, Food Chemistry, University of Münster, Münster, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Herzog R, Schwudke D, Schuhmann K, Sampaio JL, Bornstein SR, Schroeder M, Shevchenko A. A novel informatics concept for high-throughput shotgun lipidomics based on the molecular fragmentation query language. Genome Biol 2011; 12:R8. [PMID: 21247462 PMCID: PMC3091306 DOI: 10.1186/gb-2011-12-1-r8] [Citation(s) in RCA: 290] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 01/04/2011] [Accepted: 01/19/2011] [Indexed: 01/27/2023] Open
Abstract
Shotgun lipidome profiling relies on direct mass spectrometric analysis of total lipid extracts from cells, tissues or organisms and is a powerful tool to elucidate the molecular composition of lipidomes. We present a novel informatics concept of the molecular fragmentation query language implemented within the LipidXplorer open source software kit that supports accurate quantification of individual species of any ionizable lipid class in shotgun spectra acquired on any mass spectrometry platform.
Collapse
Affiliation(s)
- Ronny Herzog
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | | | | | | | | | | | | |
Collapse
|
45
|
Endocytosis and retrograde transport of Shiga toxin. Toxicon 2010; 56:1181-5. [DOI: 10.1016/j.toxicon.2009.11.021] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Accepted: 11/17/2009] [Indexed: 01/22/2023]
|
46
|
Mahfoud R, Manis A, Binnington B, Ackerley C, Lingwood CA. A major fraction of glycosphingolipids in model and cellular cholesterol-containing membranes is undetectable by their binding proteins. J Biol Chem 2010; 285:36049-59. [PMID: 20716521 PMCID: PMC2975227 DOI: 10.1074/jbc.m110.110189] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 07/23/2010] [Indexed: 11/06/2022] Open
Abstract
Glycosphingolipids (GSLs) accumulate in cholesterol-enriched cell membrane domains and provide receptors for protein ligands. Lipid-based "aglycone" interactions can influence GSL carbohydrate epitope presentation. To evaluate this relationship, Verotoxin binding its receptor GSL, globotriaosyl ceramide (Gb(3)), was analyzed in simple GSL/cholesterol, detergent-resistant membrane vesicles by equilibrium density gradient centrifugation. Vesicles separated into two Gb(3/)cholesterol-containing populations. The lighter, minor fraction (<5% total GSL), bound VT1, VT2, IgG/IgM mAb anti-Gb(3), HIVgp120 or Bandeiraea simplicifolia lectin. Only IgM anti-Gb(3), more tolerant of carbohydrate modification, bound both vesicle fractions. Post-embedding cryo-immuno-EM confirmed these results. This appears to be a general GSL-cholesterol property, because similar receptor-inactive vesicles were separated for other GSL-protein ligand systems; cholera toxin (CTx)-GM1, HIVgp120-galactosyl ceramide/sulfatide. Inclusion of galactosyl or glucosyl ceramide (GalCer and GlcCer) rendered VT1-unreactive Gb(3)/cholesterol vesicles, VT1-reactive. We found GalCer and GlcCer bind Gb(3), suggesting GSL-GSL interaction can counter cholesterol masking of Gb(3). The similar separation of Vero cell membrane-derived vesicles into minor "binding," and major "non-binding" fractions when probed with VT1, CTx, or anti-SSEA4 (a human GSL stem cell marker), demonstrates potential physiological relevance. Cell membrane GSL masking was cholesterol- and actin-dependent. Cholesterol depletion of Vero and HeLa cells enabled differential VT1B subunit labeling of "available" and "cholesterol-masked" plasma membrane Gb(3) pools by fluorescence microscopy. Thus, the model GSL/cholesterol vesicle studies predicted two distinct membrane GSL formats, which were demonstrated within the plasma membrane of cultured cells. Cholesterol masking of most cell membrane GSLs may impinge many GSL receptor functions.
Collapse
Affiliation(s)
- Radhia Mahfoud
- From the Division of Molecular Structure and Function, Research Institute, and
| | - Adam Manis
- From the Division of Molecular Structure and Function, Research Institute, and
- the Departments of Laboratory Medicine & Pathology and
| | - Beth Binnington
- From the Division of Molecular Structure and Function, Research Institute, and
| | - Cameron Ackerley
- the Department of Pediatric Laboratory Medicine, The Hospital for Sick Children, Ontario M5G 1X8 and
| | - Clifford A. Lingwood
- From the Division of Molecular Structure and Function, Research Institute, and
- the Department of Pediatric Laboratory Medicine, The Hospital for Sick Children, Ontario M5G 1X8 and
- the Departments of Laboratory Medicine & Pathology and
- Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| |
Collapse
|
47
|
Verotoxin-1 treatment or manipulation of its receptor globotriaosylceramide (gb3) for reversal of multidrug resistance to cancer chemotherapy. Toxins (Basel) 2010; 2:2467-77. [PMID: 22069561 PMCID: PMC3153170 DOI: 10.3390/toxins2102467] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Revised: 10/15/2010] [Accepted: 10/19/2010] [Indexed: 01/08/2023] Open
Abstract
A major problem with anti-cancer drug treatment is the development of acquired multidrug resistance (MDR) of the tumor cells. Verotoxin-1 (VT-1) exerts its cytotoxicity by targeting the globotriaosylceramide membrane receptor (Gb3), a glycolipid associated with multidrug resistance. Gb3 is overexpressed in many human tumors and tumor cell lines with inherent or acquired MDR. Gb3 is co-expressed and interplays with the membrane efflux transporter P-gp encoded by the MDR1 gene. P-gp could act as a lipid flippase and stimulate Gb3 induction when tumor cells are exposed to cancer chemotherapy. Recent work has shown that apoptosis and inherent or acquired multidrug resistance in Gb3-expressing tumors could be affected by VT-1 holotoxin, a sub-toxic concentration of the holotoxin concomitant with chemotherapy or its Gb3-binding B-subunit coupled to cytotoxic or immunomodulatory drug, as well as chemical manipulation of Gb3 expression. The interplay between Gb3 and P-gp thus gives a possible physiological approach to augment the chemotherapeutic effect in multidrug resistant tumors.
Collapse
|
48
|
Protein toxins from plants and bacteria: Probes for intracellular transport and tools in medicine. FEBS Lett 2010; 584:2626-34. [DOI: 10.1016/j.febslet.2010.04.008] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 04/07/2010] [Indexed: 01/07/2023]
|
49
|
Pust S, Dyve AB, Torgersen ML, van Deurs B, Sandvig K. Interplay between toxin transport and flotillin localization. PLoS One 2010; 5:e8844. [PMID: 20107503 PMCID: PMC2809741 DOI: 10.1371/journal.pone.0008844] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Accepted: 01/06/2010] [Indexed: 11/18/2022] Open
Abstract
The flotillin proteins are localized in lipid domains at the plasma membrane as well as in intracellular compartments. In the present study, we examined the importance of flotillin-1 and flotillin-2 for the uptake and transport of the bacterial Shiga toxin (Stx) and the plant toxin ricin and we investigated whether toxin binding and uptake were associated with flotillin relocalization. We observed a toxin-induced redistribution of the flotillins, which seemed to be regulated in a p38-dependent manner. Our experiments provide no evidence for a changed endocytic uptake of Stx or ricin in cells silenced for flotillin-1 or -2. However, the Golgi-dependent sulfation of both toxins was significantly reduced in flotillin knockdown cells. Interestingly, when the transport of ricin to the ER was investigated, we obtained an increased mannosylation of ricin in flotillin-1 and flotillin-2 knockdown cells. The toxicity of both toxins was twofold increased in flotillin-depleted cells. Since BFA (Brefeldin A) inhibits the toxicity even in flotillin knockdown cells, the retrograde toxin transport is apparently still Golgi-dependent. Thus, flotillin proteins regulate and facilitate the retrograde transport of Stx and ricin.
Collapse
Affiliation(s)
- Sascha Pust
- Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
- Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Anne Berit Dyve
- Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
- Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Maria L. Torgersen
- Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
- Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Bo van Deurs
- Structural Cell Biology Unit, Department of Cellular and Molecular Medicine, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Kirsten Sandvig
- Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
- Department of Biochemistry, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
- * E-mail:
| |
Collapse
|
50
|
Globotriaosyl ceramide receptor function - Where membrane structure and pathology intersect. FEBS Lett 2009; 584:1879-86. [DOI: 10.1016/j.febslet.2009.11.089] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Revised: 11/25/2009] [Accepted: 11/26/2009] [Indexed: 11/30/2022]
|